Process for producing a chlorinated C3-6 alkane

Abstract

Disclosed is a process for producing a chlorinated C3-6 alkane comprising providing a reaction mixture comprising an alkene and carbon tetrachloride in a principal alkylation zone to produce chlorinated C3-6 alkane in the reaction mixture, and extracting a portion of the reaction mixture from the principal alkylation zone, wherein:a) the concentration of the chlorinated C3-6 alkane in the reaction mixture in the principal alkylation zone is maintained at a level such that the molar ratio of chlorinated C3-6 alkane:carbon tetrachloride in the reaction mixture extracted from the alkylation zone does not exceed 95:5 when the principal alkylation zone is in continuous operation; and/orb) the reaction mixture extracted from the principal alkylation zone additionally comprises alkene and the reaction mixture is subjected to a dealkenation step in which at least about 50% or more by weight of the alkene present in the reaction mixture is extracted therefrom and at least about 50% of the extracted alkene is fed back into the reaction mixture provided in the principal alkylation zone; and/orc) the reaction mixture present in the principal alkylation zone and extracted from the principal alkylation zone additionally comprises a catalyst, and the reaction mixture extracted from the principal alkylation zone is subjected to an aqueous treatment step in which the reaction mixture is contacted with an aqueous medium in an aqueous treatment zone, a biphasic mixture is formed and an organic phase comprising catalyst is extracted from the biphasic mixture.

The invention claimed is: 
     
       1. A process for producing a chlorinated C 3-6  alkane comprising providing a reaction mixture comprising an alkene, carbon tetrachloride and a catalyst in an alkylation zone to produce chlorinated C 3-6  alkane in the reaction mixture, and extracting a portion of the reaction mixture from the alkylation zone, wherein:
 the concentration of the chlorinated C 3-6  alkane in the reaction mixture in the alkylation zone is maintained at a level such that the molar ratio of chlorinated C 3-6  alkane:carbon tetrachloride in the reaction mixture extracted from the alkylation zone does not exceed 95:5 when the alkylation zone is in continuous operation; 
 wherein the reaction mixture extracted from the alkylation zone is subjected to an aqueous treatment step with diluted hydrochloric acid in which a biphasic mixture is formed and an organic phase comprising the catalyst is extracted from the biphasic mixture. 
 
     
     
       2. The process of  claim 1 , wherein the alkene is ethene, propene and/or chlorinated propene. 
     
     
       3. The process of  claim 1 , wherein the chlorinated C 3-6  alkane is 1,1,1,3-tetrachloropropane. 
     
     
       4. The process of  claim 1 , wherein the catalyst is a metallic catalyst, further comprising an organic ligand. 
     
     
       5. The process of  claim 4 , wherein the organic ligand is tributylphosphate. 
     
     
       6. The process of  claim 1 , wherein the organic phase extracted from the biphasic mixture is fed back to the alkylation zone. 
     
     
       7. A process for producing 1,1,1,3-tetrachloropropane, comprising providing a reaction mixture comprising ethene, carbon tetrachloride, a metallic catalyst and an organic ligand in an alkylation zone to produce 1,1,1,3-tetrachloropropane in the reaction mixture, and extracting a portion of the reaction mixture from the alkylation zone, wherein
 the reaction mixture extracted from the alkylation zone is subjected to an aqueous treatment step with diluted hydrochloric acid, in which a biphasic mixture is formed and an organic phase is extracted from the biphasic mixture; and 
 the organic phase extracted from the biphasic mixture comprises carbon tetrachloride, 1,1,1,3-tetrachloropropane, tetrachloropentane and the organic ligand.